Deakin University's Steve Ogden-Barnes said self-help retailers selling items where little profit is made were more susceptible than ever to having products stolen.

Mr Ogden-Barnes said based on research in other countries theft may be as high as five times more likely at unattended checkouts than when a cashier is involved.

"It's fairly significant and if it turns out to be reflective of an Australian experience it may be a fairly damaging figure," he said.

While staff numbers can be minimised or 're-deployed' through self-service Mr Ogden-Barnes warned retailers would also have to explore spending more on security.

"There isn't a retailer yet who's entirely eradicated theft and many retailers have to accept between one and two per cent of all sales are lost," he said. "In a low margin industry operating on net margins of between two and six per cent, in a big volume industry like retail those small figures can have a big impact."

In March the Australian Retail Association [ARA] reported that retailers lost $7.5 billion to theft - a 50 per cent increase from 2009.

But ARA Executive Director, Russell Zimmerman said economic hardship had more likely led to the rise in retail theft.

"New self-checkouts are fairly accurate ... but it doesn't matter what model you use people will work out ways to beat the system. Particularly when you're in an environment where things are difficult or consumers are feeling the pinch, thefts go up automatically."

Mr Ogden-Barnes said businesses needed to be wary of removing staff from automated checkout points.

"Any smart retailer should really have people at or around the checkout keeping an eye on things," he said. The danger is when you introduce self-checkout and technology and then basically just leave that whole area alone. That's asking for trouble.

He added supermarkets were already employing safeguards to catch thieves such as video cameras at exit points.

"Next time you're in the queue look around and look up. You may see a security camera in the ceiling above the self-checkouts," he said. "There are other technologies around the corner. One is a tunnel scanner which is going to be more like putting your luggage through a baggage scanner at an airport just to ensure everything is scanned."

Woolworths were the first supermarket to introduce self-serve checkout systems in 2008 but have recently scaled back their numbers in inner-city stores to speed up customer service.